This happened to me on my C28 shortly after I bought her(used). My wife went below & saw water overflowing the bilge onto the cabin sole. We stopped the boat & used the manual bilge pump to empty the water out. Back at the slip I saw what the problem was. The exit hose went from the bilge pump up to the manual pump,but instead of then going directly to the discharge hole, it led back down to the hull(where it was attached) & then up to the hole, forming a u shaped loop. A design flaw on the C28 which was corrected on the Mk II has the discharge hole under water when sailing or motoring fast enough. This caused a hydraulic effect which back siphoned water into the bilge. While the bilge pump was working, what was happening remained unknown. When the bilge pump failed the water overflowed the bilge onto the sole. I disconected the hose from the hull & raised it as high as I could to allow a more direct discharge to the exit. This works fine now under most conditions, but I kno! w that if I will be going downwind & doing more than 6 knots, some water will still enter the bilge, so under those conditions I stick a sponge in the discharge hole & no water in the bilge. Lew C28 #253 -----Original Message----- From: [EMAIL PROTECTED] To: [email protected] Sent: Fri, 29 Jun 2007 1:19 pm Subject: catalina27-talk: Vacuum breaker valve
John Oppenheimer wrote: My 1985 routes the bilge pump line from the stern through hull through the rear lazarette floor to a strap as high as possible in the rear lazarette, back through the floor, and then to the bilge pump. This raised line keeps water from siphoning back through. John, I think what you have IS a syphon. If something happens to put your stern discharge below water, and your bilge pump quits in the middle of a discharge, then water will get sucked back into the boat. ?What you need at the high point in your loop is called a vacuum breaker, it seals on positive pressure (pumping out) but opens on a vacuum <the syphon effect>. ?Many marine head discharge lines have them for this reason. Jim ?McEwen ?(getting ready for the 4th on) Tequila Chica, Dana Point, CA ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.
